Fire extinguisher



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FIRE EXTINGUISHER Filed July 26, 1954 5 Sheets-Sheet 3 FIG. 6

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4M (AMM- United States Patent FIRE EXTINGUISHER Ralph W. ustin, Weymouth, Mass., assiguor to Process Engineering Inc., Somerville, Mass., a corporation of Massachusetts Application July 26, 1954, Serial No. 445,857

3 Claims. (Cl. 169-32) This invention relates to a fire extinguisher.

In general, the object of the invention is to provide a novel and improved fire extinguisher of the carbonateacid type wherein provision is made for controlling the mixture of the acid and carbonate, and consequently the production of gas pressure, to enable the extinguishing liquid to be expelled from the extinguisher under a relatively high and substantially uniform pressure over a substantial period of time and to thereby enable the operator to direct the stream at the fire from a substantial distance therefrom.

With this general object in view and such others as may hereinafter appear, the invention consists in the novel fire extinguisher and in the structure, arrangement and combinations of parts hereinafter described and particularly defined in the claims at the end of this specification.

In the drawings:

Fig. 1 is a vertical sectional view of a portion of a fire extinguisher embodying the invention;

Fig. 2 is a plan view of the extinguisher shown in Fig. 1 with the cap removed;

Figs. 3 and 4 are views similar to Figs. 1 and 2 of a modified form of the extinguisher shown in Figs. 1 and 2; and

Figs. 5 and 6 are graphs illustrative of the operation of a conventional soda-acid type of extinguisher of prior art and of an extinguisher of the type forming the subject matter of the present invention respectively.

In general the present invention relates to an extinguisher of the carbonate-acid type wherein a carbonateacid liquid is stored within the usual extinguisher casing and wherein the acid is stored in a special acid receptacle which is suspended within the upper portion of the casing. The acid receptacle is provided with a discharge opening through which the acid may pass when the extinguisher is inverted and with a lateral flange surrounding the upper portion of the acid receptacle which is arranged to cooperate with the casing to provide a carbonate-acid mixing chamber between the flanged acid receptacle and the usual cap member, the latter being removably secured upon the mouth portion of the casing. In accordance with the present invention the flanged portion is provided with a plurality of openings or holes disposed in spaced relation around the casing, and the total area of the openings in the flanged portion is arranged to lie within the range of about 3 to 6 times the area of the discharge opening from the acid bottle into the carbonateacid mixing chamber. With this construction when the extinguisher is operated it has been found that the extinguishing liquid is expelled from the extinguisher by relatively high gas pressure which remains fairly constant and at a substantially high value over a relatively long period of time, sufficient for the operation of the extinguisher, thus enabling the operator to use the extinguisher at a substantial distance from the fire and overcome the tendency which has heretofore existed in extinguishers of the soda-acid type of a rapid drop in gas 2,751,025 Patented June 19, 1956 "ice pressure and with the resulting diminished stream as the extinguisher is operated.

Referring now to the drawings and particularly to Figs. 1 and 2 illustrating one of the embodiments of the invention, 10 represents the extinguisher casing which is provided with the usual discharge nozzle 12 and an open mouth portion indicated generally at 14 formed by an externally threaded neck portion 16 upon which the usual form of threaded cap member 18 is screwed to normally close the mouth of the container. The extinguisher casing normally contains the extinguishing liquid, such as water, in which is dissolved any usual or preferred carbonate charge according to the size and type of extinguisher.

Provision is made for suspending an acid receptacle in the upper portion of the extinguisher casing, and as illustrated in Figs. 1 and 2, a conventional form of acid bottle 20 having a threaded neck portion 22 is screwed into a molded member 24, preferably of rubber or similar material having some degree of flexibility and resilience. The molded member 24 is provided with a discharge opening 26, preferably located centrally thereof and arranged to communicate with the open mouth of the acid bottle 20. The molded member 24 is provided with an internally threaded bore into which the threaded neck of the acid bottle is screwed to suspend the acid bottle from the molded member 24, and the latter is provided with a flange 28 of a size to snugly fit within the mouth of the extinguisher and to rest upon projecting lugs 30 forming an annular support for the flange and to thereby suspend the acid bottle and the molded member in the position illustrated in Fig. 1. The cap member 18 is preferably provided with depending lugs 32 which engage the upper surface of the flange, as illustrated, to hold the flange firmly upon the supporting annular shoulder 30. The laterally extended flange of the molded member 24 is provided with a series of spaced holes or openings 35 therethrough forming passageways for the admission of the carbonate solution into the mixing chamber 36 formed between the cap and the molded member 24. When the extinguisher is inverted for operation, the acid solution emerges through the opening 26 into the mixing chamber to thereby enable the gas-producing reaction between the acid and the carbonate solution to take place and to permit the gas to pass through the openings 35 into the extinguisher and building up the required gas pressure for the expulsion of the extinguishing liquid through the discharge nozzle 12.

In a modified form of the invention illustrated in Figs. 3 and 4 the acid receptacle is preferably formed in one piece and may be molded to provide the discharge opening 26 and the series of openings 35 in the flanged portion 28, as above described. Preferably, the acid receptacle possesses some degree of resiilence and may be of rubber, plastic or similar moldable acid-resisting material.

Referring now to Fig. 5 which graphically illustrates the curve of gas pressure against time, the curve was obtained as a result of tests of an average 2 /2 gallon loose stopple soda-and-acid extinguisher, such as is now on the market and in extensive commercial use. The curve is plotted in pounds pressure per square inch against time. It will be observed that starting from zero when the extinguisher is inverted, the pressure rapidly develops within the first 5 seconds, reaching a maximum of lbs. per square inch after 10 seconds,and then the pressure rapidly drops during the period fro-m 10 to 60 seconds from this maximum of 90 lbs. down to approximately 22 lbs. per square inch. The effect of this on the performance of these prior art extinguishers is that the distance through which the stream is expelled from the extinguisher rapidly diminishes following the inversion of the extinguisher so that the operator is required to gradu- & ally approach the fire in order that the extinguishing stream may reach the fire and serve to extinguish the same.

In accordance with the present invention, and as illustrated in both of the modifications shown in Figs. 1 and 2 and Figs. 3 and 4-, I have found that by eliminating the stopple and providing the acid-receptacle structure disclosed in which the acid-carbonate mixing chamber is formed between the flanged portion of the acid receptacle and the cap member and by so proportioning the area of discharge from the acid receptacle into the acid-carbonate mixing chamber with relation to the area of the openings in the flanged portion of the acid receptacle through which the carbonate may be introduced into the mixing chamber, it is possible to greatly improve the operating characteristics of an acid-carbonate type of extinguisher. I have found that the total area of the openings in the flanged portion of the extinguisher should lie within the range of about 3 to 6 times the area of the discharge opening from the acid receptacle, and preferably should be about 5 times such area. In Fig. 6 I have illustrated a graph showing the operating characteristics determined as the result of a number of tests of a 2 /2 gallon water filled cageless extinguisher of the construction shown in either Figs. 1 or 3 wherein it will be observed that after the operation or inversion of the extinguisher, the pressure rapidly builds up within the first 5 seconds to a substantial value of between 45 and 50 lbs. and then continues to build up, reaching its maximum after the lapse of nearly one-half of the total operating time of the extinguisher and then falling off gradually as the extinguisher continues to be operated for the remainder of the 60- second period to a pressure slightly below 45 lbs., and as a result it is possible to operate an extinguisher embodying the present invention without experiencing the usual rapid decrease in the projection of the stream from the extinguisher.

Having thus described the invention, what is claimed 1. A fire extinguisher of the carbonate-acid type having an extinguisher casing for holding the carbonated extinguishing liquid provided at the upper end with an open mouth and a removable cap member closing the mouth, an acid receptacle suspended within the upper portion of the casing and having a lateral flange surround ing the upper portion thereof cooperating in engagement with the side walls of the casing to provide a carbonate-acid mixing chamber between the flanged acid receptacle and the cap member, said acid receptacle having a widely flaring discharge mouth and a substantially smaller discharge throat disposed a substantial distance below the top of the flange for controlling the flow of acid from the acid receptacle when the extinguisher is operated, said flange being provided with a plurality of openings disposed in spaced relation around the same for admitting carbonate liquid into the mixing chamber and the exit of carbon dioxide from the mixing chamber to within the casing, said flaring mouth terminating at the plane of the top of the openings in the flange through which the carbonate liquid passes into the body of the extinguisher whereby to assist in the substantially uniform flow of acid into a position to react with the carbonate liquid entering the mixing chamber, the total area of the openings in the flanged portion of the acid receptacle lying within the range of about 3 to 6 times the area of the discharge throat from the acid receptacle into the mixing chamber whereby the gas pressure developed within the casing after the extinguisher is inverted diminishes gradually from its maximum.

2. A fire extinguisher of the carbonate-acid type having an extinguisher casing for holding the carbonated extinguishing liquid provided at the upper end with an open mouth and a removable cap member closing the month, an acid receptacle suspended within the upper portion of the casing and having a lateral flange surrounding the upper portion thereof cooperating in engagement with the side walls of the casing to provide a carbonateacid mixing chamber between the flanged acid receptacle and the cap member, said acid receptacle having a widely flaring discharge mouth and a substantially smaller dis charge throat disposed a substantial distance below the top of the flange for controlling the flow of acid from the acid receptacle when the extinguisher is operated, said flange being provided with a plurality of openings disposed in spaced relation around the same for admitting carbonate liquid into the mixing chamber and the exit of carbon dioxide from the mixing chamber to within the casing, said flaring mouth terminating at the plane of the top of the openings in the flange through which the carbonate liquid passes into the body of the extinguisher whereby to assist in the substantially uniform flow of acid into a position to react with the carbonate liquid entering the mixing chamber, the total area of the openings in the flanged portion of the acid receptacle lying within the range of about 5 times the area of the discharge throat from the acid receptacle into the mixing chamber whereby the gas pressure developed within the casing after the extinguisher is inverted diminishes gradually from its maximum.

3. A fire extinguisher of the carbonate'acid type having an extinguisher casing for holding the carbonated extinguishing liquid provided at the upper end with an open mouth, and a removable cap member closing the mouth, a resilient and flexible acid-resisting receptacle suspended within the upper portion of the casing, and with an integral flange surrounding the upper portion thereof cooperating in engagement with the side walls of the casing to provide a carbonate-acid mixing chamber between the flanged acid receptacle and the cap member, said acid receptacle having a widely flaring discharge mouth and a substantially smaller discharge throat disposed a substantial distance below the top of the flange for controlling the flow of acid from the acid receptacle when the extinguisher is operated, said flange being provided with a plurality of openings disposed in spaced relation around the same for admitting carbonate liquid into the mixing chamber and the exit of carbon dioxide from the mixing chamber to within the casing, said flaring mouth terminating at the plane of the top of the openings in the flange through which the carbonate liquid passes into the body of the extinguisher whereby to assist in the substantially uniform flow of acid into a position to react with the carbonate liquid entering the mixing chamber, the total area of the openings in the flanged portion of the acid receptacle lying within the range of about 3 to 6 times the area of the discharge throat from the acid receptacle into the mixing chamber whereby the gas pressure developed within the casing after the extinguisher is inverted diminishes gradually from its maximum.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A FIRE EXTINGUISHER OF THE CARBONATE-ACID TYPE HAVING AN EXTINGUISHER CASING FOR HOLDING THE CARBONATED EXTINGUISHING LIQUID PROVIDED AT THE UPPER END WITH AN OPEN MOUTH AND A REMOVABLE CAP MEMBER CLOSING THE MOUTH, AN ACID RECEPTACLE SUSPENDED WITHIN THE UPPER PORTION OF THE CASING AND HAVING A LATERAL FLANGE SURROUNDING THE UPPER PORTION THEREOF COOPERATING IN ENGAGEMENT WITH THE SIDE WALLS OF THE CASING TO PROVIDE A CARBONATE-ACID MIXING CHAMBER BETWEEN THE FLANGED ACID RECEPTACLE AND THE CAP MEMBER, SAID ACID RECEPTACLE HAVING A WIDELY FLARING DISCHARGE MOUTH AND A SUBSTANTIALLY SMALLER DISCHARGE THROAT DISPOSED A SUBSTANTIAL DISTANCE BELOW THE TOP OF THE FLANGE FOR CONTROLLING THE FLOW OF ACID FROM THE ACID RECEPTACLE WHEN THE EXTINGUISHER IS OPERATED, SAID FLANGE BEING PROVIDED WITH A PLURALITY OF OPENINGS DISPOSED IN SPACED RELATION AROUND THE SAME FOR ADMITTING CARBONATE LIQUID INTO THE MIXING CHAMBER AND THE EXIT OF CARBON DIOXIDE FROM THE MIXING CHAMBER TO WITHIN THE CASING, SAID FLARING MOUTH TERMINATING AT THE PLANE OF THE TOP OF THE OPENINGS IN THE FLANGE THROUGH WHICH THE CARBONATE LIQUID PASSES INTO THE BODY OF THE EXTINGUISHER WHEREBY TO ASSIST IN THE SUBSTANTIALLY UNIFORM FLOW OF ACID INTO A POSITION TO REACT WITH THE CARBONATE LIQUID ENTERING THE MIXING CHAMBER, THE TOTAL AREA OF THE OPENINGS IN THE FLANGED PORTION OF THE ACID RECEPTACLE LYING WITHIN THE RANGE OF ABOUT 3 TO 6 TIMES THE AREA OF THE DISCHARGE THROAT FROM THE ACID RECEPTACLE INTO THE MIXING CHAMBER WHEREBY THE GAS PRESSURE DEVELOPED WITHIN THE CASING AFTER THE EXTINGUISHER IS INVERTED DIMINISHES GRADUALLY FROM ITS MAXIMUM. 